1. Field of the Invention
This invention generally relates to integrated circuit (IC) fabrication and, more particularly, to a nanorod sensor with both electrodes formed on the top surface, and a process for fabricating the nanorod sensor.
2. Description of the Related Art
Recently, the fabrication of nanowires has been explored due to its potential importance as a building block in nano, microelectromechanical (MEM), and nanoelectromechanical NEM device applications. For example, researchers associated with Charles Lieber have reported the synthesis of a variety of semiconductor nanowires made from materials such as silicon (Si), Si-germanium (SiGe), InP, and GaN, for use in building nano-computing system. Other groups have also reported using templates structures to grow metallic nanowires made of materials such as Ni, NiSi, Au, and Pt. Metallic nanowires can be used as interconnections and the sharp tips of the nanowire make them effective for field emission purpose. Metal oxide nanowires/rods/tubes have been used in gas sensor applications due to their advantages of low power, low cost, high sensitivity, and high stability.
One key problem has been with the integrity of nanorod sensors, as the nanorods are inherent fragile. As a result, designs have been limited to less effective two-dimensional (2D) nanorod fields. However, even 2D nanorod gas sensors have been difficult to fabricate in large scale production with reproducibility.
It would be advantageous if a three-dimensional (3D) nanorod gas sensor structure could be made using conventional IC processes.